Whale death prompts call for nautical speed limit

The death of a blue whale and her calf that washed ashore in San Mateo County this week has prompted an environmental group to propose a 10-knot speed limit within the National Marine Sanctuaries.

An expert with the Marine Mammal Center says it appears the whale was killed after colliding with a ship. Pacific Environment Marine Sanctuaries says the whale's death highlights the need to protect whales from ships.

California's coast hosts the largest remaining population of endangered blue whales on earth.